Automatic safety fuel system



March 10, 1942; v D SAMIRAN 2,275,471

AUTOMATIC SAFETY FUEL SYSTEM Filed July 31, 1940 2 Sheets-Sheet l March 10, 1942. D. sAMlRAN AUTOMATIC SAFETY FUEL SYSTEM Filed July 31, 1940 2 Sheets-Sheet 2 INVENTOR. flea/M Wm Patented Mar. 10, 1942 UNITED STAT 2,275,471 AUTOMATIC SAFETY FUEL SYSTEM David Samlran, Fairfield, Ohio Application July 31, 1940,

27 Claims.

Serial No. 348,969

(Granted under the act amended April 30,

The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

The present invention relates in general to fuel systems provided with a plurality of separate fuel sources and more particularly to fuel systems in which the contents of a plurality of fuel containers'are automatically connected in predetermined order. to a source of fuel consumption, such as an airplane engine or the like, the present application being a continuation in part of my copending application Serial No. 261,542, filed March 13, 1939.

In fuel systems having selector valves rotated by an electric motor or the like, it is desirable to have the valve rotated slowly so that it can be promptly stopped when the desired ports are in exact registry with each other. If the selector valve rotates slowly throughout its operating cycle, however, considerable time periods of delay are experienced when passing through successive positions of the selector valve, during which periods of time fuel is shut off through the valve and the fuel pump with fuel. From this standpoint, it is desirable to have the, selector valve rotate quickly from one position to the next and the two desirable characteristics just considered are obviously in confiict with each other and constitute a failure of the ordinary type of automatically operable selector valve.

It is therefore an object of my present invention to provide a selector valve operating mechanism wherein the motor for operating the selector valve may be normally operated at high speed to minimize the period of time between successive selector valve positions and to provide means to slow down the rotation of the motor as the ports of the valve approach a reglstering position whereby the valve can be promptly and accurately stopped at the registering position.

A further object is to provide means in the form of an electrically operated clutch for the purpose of effecting exact registration of the selector valve ports, whereas there is a possibility of their overrunning as a result of momentum of themotor after it is deenergized if such clutch werenot provided.

Still a further object is to provide, in connection with a motor operated selector valve wherein the motor is controlled by a fuel pressure responsive switch, a means to open the circuit of the switch at the completion of a selector valve is therefore unsupplied of March 3, 1883, as

operation through the medium of a solenoid or the like, so that the fuel pressure responsive switch may be conveniently located remotely with respect to the selector valve operating mechanism and synchronous operation effected through electric wiring connections to the solenoid.

Still a further object is to provide an automatic fuel system having a safety feature i'n that, when the selector valve rotates to any position corresponding to a fuel tank that is inadvertently empty, or empty as a result of a bullet hole leak or the like, the selector valve will move on to the next fuel tank containing fuel without stopping at the empty tank position. I

Another object is to provide a switch in connection with each fuel tank operable to render the mechanism that slows down the valve at registering position ineffective, so that the selector valve will be quickly moved on past an empty tank position without the operation being slowed down as when effecting registration of the selector valve ports when the tank to which the selector valve is being adjusted contains fuel.

Still another object is to provide a fuel system including a selector valve and operating mechanism therefor wherein the valve is rotated at high speed between successive positions to cut time loss to a minimum between adjustments of the selector valve to new sources of fuel supply and a fuel tank switch on each fuel tank cooperating with a commutator on the selector valve to shunt out a resistance which, when not so shunted, slows down the motor at selector valve registering positions.

Other objects and advantages of my inventionwill become apparent from the following description taken in connection with the accompanying drawings, it being clearly understood that the same are by way of illustration and example only and'are not to be taken as in any way limiting the spirit and scope of my invention, which are to be limited only by the prior art and by the terms of the appended claims.

Referring to the drawings, in which numerals of like character designate similar parts throughout the several views:

Figure 1 is a diagrammatic representation of an automatic safety fuel system embodying my invention;

Figure 2 is a diagrammatic view of the fuel pressure responsive switch of my system showing it in a position assumed as a result of fuel pressure drop; 4

Figure 3 is a similar view of the switch showing I it in the position assumed as a result of subsequent building up of fuel pressure therein;

Figure 4 is a similar View of a portion of Figure 1 showing a pair of cams and a commutator of my system in a diiferent position as assumed when the selector valve has rotated nearly to its next successive position with respect to that shown in Figure l, and

Figure 5 is a sectional view through a selector valve of my system showing diflerent positions thereof for movement between successive selector valve positions and port operable wobble pump I8. The outlet of the pump I 1 is connected through a switch pressure regulator I! to an inlet pipe of an air-vapor eliminator 2|. The outlet of the wobble pump [8 is also connected to the inlet pipe 20.

The air-vapor eliminator 2| has a connection 22 in the vapor outlet 26 for discharging air and vapor eliminated from the fuel within the eliminator 2!.

fuel system may be connected with an engine or other fuel consuming device. In some types of engines a carburetor would be substituted for the fuel injector 23.

For operating the selector valve I0 I provide a shaft 27. The shaft 21 has secured thereto a with clutch teeth toothed face cooperate. square shaft 32 which is pressed as by a spring 33 in the 3!) of the pinion 29.

The square shaft 32 is ably associated with journaled for rotation slidably and non-rotata bevel gear 34 suitably For engaging the clutch disc 3| with the clutch teeth of the pinion 29, I provide a solenoid 36 in which is slidably mounted a plunger 31. A stem 38 extends from the plunger 31 and is adapted to engage the back of the clutch disc pressure responsive switch S. The switch S has a bellows chamber 39, in which is mounted a collapsible bellows 40. The bellows 40 collapses against the tension of a spring ll and thereby actuates a stem 42 in a left-hand direction. A conduit 43 extends from the bellows chamber 39 to the switch pressure regulator H, which regulator furnishes fuel under a substantially constant pressure to 'the conduit 43 as long as the pump I 5 is receiving a predetermined quantity of fuel or fuel in excess of such quantity. When the pump l6 runs out of fuel, drops within the bellows chamber 39 so that the spring 4! retracts the stem 42.

parts of the switch S.

When the fuel pressure drops within the bellows chamber 39, the switch carriage 49- will be moved in a right-hand direction by the spring 4 I, whereupon closure ever the solenoid 52 is energized the plunger 53 is drawn into the solenoid against the tension of the spring 51 to remove the cam lobe 55 from registry with the cam lobe 56, as shown for instance by dotted lines in Figure 2 and in Figure 3.

negative terminal 84 of a terminal panel 80. The ignition switch 08 is the one used for the ignition system of the engine on which my fuel system is installed, an ignition wire 80 extending from the switch to the ignition system. I connect the ignition switch 08 in the circuit of my fuel system in this manner so that there can be no undesired operation of the fuel system during a time when the engine is not running, because of the ignition switch being turned off, and accordingly operation of the fuel system is not needed.

The terminal panel 80 has a control terminal 81 with which the contact 40 of the switch S is connected by a wire 88. From the control terminal 81 a wire leads to a resistance shunting switch having a stationary contact 10 and a movable contact 1|.' The contact 1| is connected by a wire 12 to one side of the motor M, the other side of which is grounded by a wire 18.

I provide a resistance element 14 shunted by the switch 101|, so that whenever the switch is open the resistance element is in series with the motor M, thereby slowing down its rotation for a purpose which will hereafter appear. To operate the switch 10--1|, I provide a cam disc 15 on the shaft 21 having cam lobes 15a, 15b and 15c. These are adapted to successively cooperate with a cam lobe 18 of the switch contact 1| to lift it from engagement with the contact 10 whenever any of the lobes 15a, 15b or 150 registers with the lobe 18.

The solenoid 52 is also controlled by the switch S through a wire 11 connected with the control terminal 61, normally opened switch contacts 18 and 19, a wire 80 and a ground wire 8|. Thus although the solenoid 52 is under control of the switch S, it can be energized only when the contacts 18 and 19 are also engaged.

The contacts 18 and 18 are controlled by a cam disc 82 having notches 82a, 82b and 820. The notches are adapted to successively receive a cam lobe 83 of the switch contact 19 to open the circuit across it and the contact 19. Rotation of the shaft 21 on which the'cam disc 82 is mounted to a position other than registry of any of the notches with the lobe 80 results in-closure of the circuit for the solenoid 52.

In addition to the resistance 14 being shunted by the switch III-1|, tacts 84 and 85 of a relay R. The contact 80 is connected by a wire 88 to one end of the resistance element 10, while the contact 85 is connected by a wire 81 to the other end thereof.

The relay R has a coil 88 connected by a wire 89 to the control terminal 81 and by a wire 80 to a threepole commutator blade 8|. The commutator blade 9| coacts with commutator segments 92a, 92b and 820 of a commutator drum 82.

' Individual blades 83, 84 and III are connected by wires 98, 91 and 88 to float switches 88, I00 and NI located at the fuel tanks I, 2 and 3, respectively. Each float switch includes a suitable float I02 responsive to the level of fuel in the tank and so connected with the float switch that when the fuel tank is nearly empty, as in the tank I of Figure 1, the float switch is nearly closed, such closing occurring just before the float rests on the bottom of the tank. In this manner each tank when empty efiects closure of its float switch so that a circuit may be established from either of the wires 98, 81' or 88 to ground wires I08, I00 or I05, respectively, of the float switches 88, I00 and IN. a

My fuel system may include an indicator light I06 connected by a we I01 to the control terit is also shunted by conwith a dial Ill.

of the motor circuit by minal 81 and a wire I08 to ground. Thus the indicator light I08 is energized any time the switch S is closed. For testing the indicator light I00, a manual testing switch I08 is provided connected by wires H0 and III between the negative terminal 84 and the indicator light.

It is desirable in an automatically operable selector valve of the character herein disclosed, to permit manual rotation of the valve to any fuel tank or to of! position. For this purpose I provide a control handle 2 on the selector valve shaft 21'having a pointer ||8 cooperating The dial Ill may be inscribed with 1, 2, 3 and off, indicating the respective fuel tanks with any one of which the selector valve may be connected, and off? position when none of the fuel tanks are connected through the selector valve with the pump supply conduit II. The handle I I2 may be operated either clockwise or counterclockwise any time desired, inasmuch as the solenoid 36, normally de-energized, results in the clutch connection -3| being inoperative. In the event that the solenoid is energized, the

handle 2 can still be rotated as desired, as the clutch teeth, held engaged by the solenoid, can ratchet past each other.

Practical operation Assuminga fuel level in the tank I as shown in Figure 1, and that further fuel is then pumped from the tank, the float I02 therein will lower and close the float switch 99. A circuit can now be traced from the ground wire I03 of the float switch 98 through elements 88, 82a, III, 80, 88, 89, 61 and 88 to the switch contact 49. The switch S, however, is open so that there is no current flow. Accordingly, the pump I6 may continue to operate for draining substantially all of the fuel from the tank I. I

When the pump I6 runs out of fuel it can no longer keep pressure up in the switch pressure regulator I9 and the conduit 43 leading to the bellows chamber of the switch S. Therefore the.

bellows l0 and moves the switch carriage to the right, as in Figure 2, thus closing the switch S. Closure of the switch S energizes the control terminal 51 from the battery 58 through the following elements: 8|, 59, 62, 08, 50, 48, 49 and 68. Therefore the relay coil 88 is energized for attracting the armature of the relay and thereby closing the contacts 84 and 85 which, however, produces no result, since the resistance element 18 is already shunted out I the switch 10--1|.

Closure of the switch S, in addition to the relay circuit just described, establishes three other circuits as follows: (1) a circuit for the motor M from the control terminal 61 through. elements 60, 10, 1|, 12 and 18; (2) a circuit for the solespring 4| expands the noid 52 from the control terminal through elements 11, 18, 19, 80 and 8|, the solenoid however remaining de-energized until the motor M has rotated the shaft 21 sufliciently for the cam notch 02 to coact with the lobe 83 and close the contacts 18 and 19. Thereupon the cam lobe 55 of the solenoid 52 will move from the full line to the dotted position of Figure 2; (3) the clutch solenoid 36 will be energized by currentv from the control terminal 51 through a wire 5 and a ground wire H6. Thus, as soon as the motor M starts to operate, the clutch solenoid is energized to operatively connect the motor with the selector valve.

With the solenoids 36 and I2 energized and themotor M operating, the selector valve will rotate from the full line position shown in Figure 5, with the port I3 of the valve plug I 2 is registry with the conduit 4 of the tank I to a position where the port l3 starts to register with the next successive conduit 5 (shown by dotted lines). The angle of travel is indicated by the dimension line H7.

As soon as the segment 92a of the commutator blade 9|, the relay coil and if the fuel tank 2 position the float switch position, the relay will not be re-energized when the commutator segment 92b bridges the blades 9| and 94 (as shown in Figure 4). When the angle of movement H! has been completed, the next cam-lobe b will open the switch 708I, thereby opening the shunt circuit therethrough for the resistance element I4 and the motor circuit will then be through the resistance element instead of directly across the closed switch contacts Ill and II. This effects slowing down of the motor M so will be de-energized, contains suflicient fuel to I00 in its open circuit with the conduit 5, the lobe 83 of the switch blade 19 will drop into the notch 8217, thus de-energizing the solenoid 52, causing it to quickly move to the position of Figure 1 for opening the switch S. This results in energized. lobe 83 of the switch blade 19 drops into the notch 82b, the lobe 76 of the switch blade 1| drops behind the lobe 15b of the cam disc 15, thus positioning the switch 701l for a subsequent operation.

From the foregoing description of the operation of my fuel system, it is obvious that the seports and is then slowed down as the ports are approaching alignment. The ports of the valve are thus gradually brought into registration and may be accurately stopped at registering position.

However, time delay as would be caused by slow movement from one port to the next is eliminated, thus speeding up the change-over from an empty tank to the next tank. ThusI secure both the advantage of quick movement from one position to the next and slow movement for port registration purposes.

When, however, the next tank, as for instance the tank 2, is empty, it is desirable to go on to At about the same time that the the third tank which, without the relay R, the

tions corresmnding to empty eliminator is designed 01' would be no fuel from l6. Accordingly, the switch S would remain in 2 instead of being carried Figure 3, and when the lobe 83 of the switch blade 19 dropped into the notch 82b, de-energization of the solenoid 52 controlled by be slowed down at the condu1t'5 because the Such slowing down of the motor introduces undesirable delay, as since the tank 2 is empty it is desirable to go on at high speed to the tank 3. float switches, the commutator and the relay arrangement has been provided and enter into the operation as follows: If the tank is empty, its float switch I00 will be closed. Accordingly, when the commutator segment 92 bridges the commutator blades 9| and 94, the relay coil 88 will be energized because the control already energized by the switch S. closure of the relay R so that, regardless of any opening of the switch 1n 1|, the resistance element M will be shunted out of the motor circuit, which circuit whenever the the selector valve will continue through all positanks and be slowed down and stopped only when a full tank position is encountered. This cuts down time loss to a to another one, a reserve air-vapor eliminator 2| is being used and the take care of a shift through several selector valve Obviously, the shorter periods 01' time requirements for the reserve supply in the elim- The commutator segments 92a, 92b, 920, are of suflicient length to pick up and close to opening of the switch the switch S if, before the lobe 83 drops into any of the notches of the cam disc 82, the fuel pressure has been built up within the switch S to move it from the position of Figure 2 to the position of Figure 3. Failure to build up such a pressure results in a recycling circuit being established to cause operation of the selector valve on past an empty tank position resulting from the pump l6 receiving air instead of fuel from said empty tank.

Any time that the operator wishes to test the indicator light I06, he may do so by manually closing the switch I09, thus providing a circuit for the indicator light I08 from the battery 58 through elements 6f, 59, 62, 64, H0, I09; III, 106 and N18 to ground. He is thus assured that current supply to automatically operate the selector valve is available and that his indicator bulb is not burned out, so that any subsequent fuel failures occurring as a result of fuel tanks becoming empty will be indicated to him by flashing on of the light I06 under control of the switch S. As soon as a selector valve operation has been completed, then the light will be extinguished due to opening of the switch S. During selector valve operation, the indicator H3 will indicate on the dial H4 What tanks are being connected to the pump and which are empty and passed up by the automatic selector valve operating mechanism.

Some changes may be made in the construction and arrangement of the parts of my device without departing from the real spirit and purpose of my invention, and it is my intention to cover by my claims any modified forms of structure or use of mechanical equivalents which may be reasonably included within their scope without sacrificing any of the advantages thereof.

I claim as my invention:

, 1. In an automatic safety fuel system having a plurality of fuel tanks, a selector valve operable to selectively connect any one of said plurality of fuel tanks with a fuel consuming device, means for operating said selector valve at relatively high speed when changing from one selector valve position to the next, a fuel pressure responsive controller for controlling said means, means for slowing down the operation of said first means when said selector valve has progressed to a position adjacent alignment of its ports, a control device for each fuel tank and operable when the tank is empty to render said means for slowing down the operation of said first means ineffective, said control device being operatively connected with said selector-valve to effect such rendering of said first means ineffective only when that tank, for a selector valve position assumed by the selector valve, is empty.

2. In an automatic safety fuel system having a plurality of fuel tanks and a fuel pump, a selector valve connected between said plurality of fuel tanks and said fuel pump, said fuel pump being operative to pump fuel to a fuel consuming device, a motor for operating said selector valve at relatively high speed when changing from one selector valve position to the next, a fuel pressure responsive switch for controlling said motor, means for slowing down the operation of said motor when said selector. valve has progressed to a position adjacent alignment of its ports, a switch for each fuel tank and operable, when the tank is empty, to render said means for slowing down the operation of said motor ineffective, and a commutator operatively connected with said selector valve and electrically connected in the circuits of said tank switches to I fuel pressure responsive effect such rendering of said means for slowing down the operation of the motor ineffective only when that tank is empty which corresponds to a selector valve position assumed by said selector valve.

3. In an automatic safety fuel system having a plurality of fuel tanks and a fuel pump operative to pump fuel to a fuel consuming device, a selector valve, a motor for operating said selector valve at relatively high speed when changing from one selector valve position to the next, a switch for controlling said motor, said selector valve, in a predetermined position, effecting opening of said switch, means for slowing down the operation of motor when said selector valve has progressed to a position adjacent alignment of its ports comprising a resistance element in series with said motor, a shunting switch for said resistance element and a cam rotatable with said selector valve to open said switch, a switch for each fuel tank and operable, when the tank is empty, to shunt said shunting switch for slowing down the operation of said motor, and a commutator operatively connected with said selector valve and electrically connected in the circuits of said tank switches to effect such shunting of said shunting switch only when that tank is empty which corresponds to a selector valve position assumed by said selector valve.

4. In an automatic safety fuel system having a plurality of fuel tanks and a fuel pump operative to pump fuel to a fuel consuming device, a selector valve, an electric motor for operating said selector valve at relatively high speed when changing from one selector valve position to the next, a fuel pressure responsive switch for controlling said motor, a resistance element connectible in series with said motor for slowing down the operation thereof when said selector valve has progressed to a position adjacent alignment of its ports, a switch for each fuel tank and operable when the tank is empty to shunt saidresistance element out of the motor circuit for slowing down the operation of said motor while said ports are beingaligned, and a commutator operatively connected with said selector valve and electrically connected in the circuits of said tank switches to effect such resistance element shunting only when the tank for a given selector valve position is empty.

5. In an automatic safety fuel system having a plurality of fuel tanks, a selector valve operable to selectively connect any one of said plurality of fuel tanks with a fuel consuming device, a prime mover for operating said selector valve at relatively high speed when changing from one selector valve position to the next, a fuel pressure responsive controller for controlling said prime mover, means for slowing down the operation of said prime mover when said selector valve has progressed to a position adjacent alignment of its ports, and means to render said means for slowing down the operation of said prime mover ineffective, said last means being operatively connected with said selector valve to effect such rendering of said prime mover ineffective only when that tank, for a selector valve position assumed by the selector valve, is empty.

6. In an automatic safety fuel system having a plurality of fuel tanks and a fuel pump, a selector valve for selectively connecting any one of said plurality of fuel tanks with said fuel pump, said fuel pump being operated to pump fuel to a fuel consuming device, a shaft for said selector said valve, a motor for rotating said shaft at a relatively high speed when changing from one selwtor valve position to the next, a fuel pressure responsive switch for controlling said motor and thereby the rotation of said shaft. a cam on said shaft cooperating with said fuel pressure switch to open the switch when the shaft assumes a position of alignment of the ports of the selector w fuel pressure has been built up esure switch, means for slowing down 1032 of said motor when the selector reg seed to n position adjacent align "ores, a switch for each fuel tank and ii-811B. is empty to render said slop down said motor, 1 said shaft and electrically :o the circuits of said tank switches.

utoLr c safety fuel system having a i and a fuel operato a fuel consuming device, a it for said seiector valve, a one: shaft at a relatively high cr ng g from one selector valve "$55, a fuel pressure responsive ion shaft a cam on said shaft rug with said fuel pressure switch to switch when the shaft valve has progressed to a position adjacent alignment of its ports, said means comprising a resistance connected in the circuit of said motor only when said shaft and thereby said selector valve assume said position adjacent alignment of the selector valve, 2, switch for each fuel tank and operable when the tank is empty to render said resistance inefiective to slow down said motor, and a commutator on responding thereto is empty.

8. In an automatic safety fuel system having a plurality of fuel tanks, between said plurality of fuel tanks and a fuel consuming device, a shaft for said selector valve, a motor for rotating said shaft at a relatively switches.

2' con oiling said motor and thereby K,

a selector valve connected I 9. In an automatic safety fuel system having atlng said selector valve at relatively high speed 78 inefi'ective, and a l switch at port when changing from one valve position to the next, a fuel pressure responsive switch for controlling, said motor, an electrically operated clutch between said motor and said selector valve and controlled by said fuel pressure respom sive switch, means for slowing de 1 tlon of said motor when said selecprogressed to a position adjacent ports, a switch for each fuel tan a when the tan empty to render Smif. l-

lment of its nected with said selector valve and electrically connected in the circuits of said tanks.

10. In an automatic safety fuel system having apl'urolity of fuel tanlrs and fuel pump, a selector valve connected between said plurality of fuel tanks and said fuel pump, said fuel pump being operative to pump fuel to a fuel consun1- in;- device, motor for operating said selector valve at relatively high speed when changing" from one selector valve position to the next, a fuel pressure responsive switch for controlling said motor, an electrically operated clutch between said motor and said selector trolled by said fuel pressure responsive switch, means for slowing down the operation of said motor when said selector valve has progressed to a position adjacent alignment of its ports, and means for opening said fuel pressure responsive alignment position.

11. In an automatic safety fuel system includ ing a plurality of fuel tanks and a fuel pump, aselector valve connecting any one of said plution of said motor ineffective.

13. In an automatic safety fuel system having a plurality of fuel tanks and a fuel pump, a selector valve connected between said plurality fuel pump, said pump beelector vai've position tothe next, a fuel pressure responsive switch for controlling said motor,

'- and means for slowing down the operation of said motor when said selector valve has progressed to a position adjacent alignment of its ports.

14. In an automatic safety fuel system having a plurality of fuel tanks and a fuel pump, a selector valve for selectively connecting any one of said fuel tanks with said fuel pump, means for operating said selector valve at relatively high speed when changing from-one selector valve position'to the next, a fuel pressure responsive controller for controlling said means, means for slowing down the operation of said first means when said selector valve has progressed to a position adjacent alignment of its ports, and means.

for operatively disconnecting said first means from said selector valve at port registering position, said last means being controlled by reason of said controller being operatively connected with said selector valve to be actuated to inoperative position thereby upon said selector valve assuming said port registering position.

l5. In an automatic safety fuel system having a plurality of fuel tanks and a fuel pump, a selector valve for selectively connecting said plurality of fuel tanks with said fuel pump, said fuel pump being operative to pump fuel to a fuel consuming device, a motor for operating said selector valve at relatively high speed when changing from one selector valve position to the next, a switch for controlling said motor, said switch being responsive to fuel pressure supplied by said pump in conjunction with positioning of said selector valve at port alignment position, and means for slowing down the operation of said motor when said selector valve has progressed to a position adjacent said port alignfor controlling said motor, saidfuel pressure responsive switch being closed by a drop of fuel pressure and carried in closed position to another position upon subsequent building up of fuel pressure, a solenoid for opening said switch when in said another position, means for controlling said solenoid comprising a switch operated in synchronism with said selector valve, and means for slowing down the operation of said motor when said selector valve has progressed to a position adjacent alignment of its ports.

19. In an automatic safety fuel system having a plurality of fuel tanks, a selector valve connected between said fuel tanks and said fuel pump, said fuel pump being operative to pump fuel to a fuel consuming device, a motor for operating said selector valve normally at relatively high speed, a fuel pressure responsive switch for controlling said motor, said fuel pressure responsive switch being closed by a predetermined drop of fuel pressure from said pump and carried in closed position to another position upon subsequent return of fuel pressure to a predetermined degree, means for opening said switch when in said another position, means operated in synchronism with the rotation of said selector valve for controlling said last means, and means for slowing down the operation of said motor when said selector valve has progressed to a ment position, said switch, in response to selector valve position, tie-energizing said motor.

16. In an automatic safety fuel system having a plurality of fuel tanks and a selector valve connected between said plurality of fuel tanks and said fuel pump, a motor for operating said selector valve at relatively high speed when changing from one selector valve position to the next,

a fuel pressure and selector valve position responsive switch for controlling said motor, an electrically operated clutch for operatively connecting said motor with said selector valve, said clutch being under control of said fuel pressure responsive switch, and means synchronized with the operation of said selector valve for slowing down the operation of said motor when said selector valve has progressed to a position adjacent alignment of its ports.

17. In an automatic safety fuel system including a plurality of fuel tanks, a selector valve connected between said plurality of fuel tanks and a fuel consuming device, a motor for operating said selector valve at relatively high speed when changing from one selector valve position to the next, a fuel pressure and selector valve position responsive switch for controlling said motor, and selector valve position responsive means for slowing down the operation of said motor when said selector valve has progressed to position adjacent alignment of its ports.

20. In an automatic safety fuel system having a plurality of fuel tanks and a fuel pump, a selector valve for selectively connecting any one of said plurality of fuel tanks with said fuel i pump, said fuel pump being operative to pump fuel to a fuel consuming device, a motor for operating said selector valve at relatively high speed when changing from one selector valve position to the next, a fuel pressure responsive switch for controlling said motor, said fuel pressure responsive switch being closed by a drop of fuel pressure and carried in closed position to another position upon subsequent rise of fuel pressure, means operated in synchronisrn with the rotation of said selector valve for opening said switch when insaid another position, and means for slowing down the operation of said motorwhen said selector valve has progressed to a position adjacent alignment of its ports.

21. In an automatic safety fuel system having a plurality of fuel tanks and a fuel pump, a selector valve connected between said plurality of fuel tanks and said fuel pump, said fuel pump operated clutch connection-between said motor and said selector valve, said clutch connection being under control of said fuel pressure responsive switch, and means responsive to selector valve position for slowing down the operation of said motor as said selector valve closely approaches port alignment position.

22. In an automatic safety fuel system having a plurality of fuel tanks and a fuel pump, a selector valve for selectively connecting any one of said plurality of fuel tanks with said fuel pump, said fuel pump being operative to pump fuel to a fuel consuming device, a motor for quickly operating said selector valve from one selector valve position to the next, means under control of said selector valve to slow down said motor at adjacent port alignment position of the valve, 2, fuel pressure and selector valve position responsive switch for controlling said motor, and an electrically operated clutch connection between said motor and said selector valve, said clutch connection being under control of said fuel pressure responsive switch.

23. In an automatic safety fuel system having a plurality of fuel tanks and a fuel pump, r. selector valve connected between said plurality of fuel tanks said fuel pump, said fuel pump being operative to pump fuel fro said valve to a fuel consuming" device, a motor for operating said selector valve at relatively high speed when changing from one selector valve position to the next, a fuel prewure responsive switch for controlling sold mot shunting switch in the clr cult of me or, a resistance shunting sold switch, said shunting switch being opened by said selector re when adjacent oort registerlug position ierehy to slow down the rotation of said sel tor valve, a switch cos 1 fuel tank, a commutat co.-.oected with selector valve and electrically connected in circuits of said switches, and a relay controlled by said commutator and shunting feet relatively high speed rotation of said selector valve past a port registering position corresponding to empty fuel tank.

In an automatic safety fuel system hava plurality of fuel tanks, a selector valve connecteo between said plurality of fuel tanks and a fuel consuming device, a motor for oper ating said selector valve at high speed when changing from one selector valve position to the next, 9. fuel pressure responsive switch. for controlling said motor, a shunting switch in the circuit of said motor, a resistance shunting said switch, said shunting switch being opened by said selector valve when adjacent port registering position whereby to slow down the'rotation of said selector valve.

25. In an automatic safety fuel system having a plurality of fuel tanks, a selector valve for selectively connecting any one of said plurality of fuel tanks with a fuel consuming,device, a motor for operating said selector valve at high speed. when changing from one selector valve position to the next, a fuel pressure responsive switch for controlling said motor, a shunting switch in the circuit of said motor, a resistance shunting said switch, said shunting switch being opened by said selector valve when adjacent port registering position whereby to slow down the rotation of said selector valve, a switch for each said resistance to of l.

sprain fuel tank, and a commutator operatively connected with said selector valve and electrically connected in the circuits of said tank switches,

shunting of said resistance to effect high speed rotation of said selector valve past a port registering position correspondin to an empty fuel tank.

26. In an automatic safety fuel system having a plurality of fuel tanks and a fuel pump, a selector valve connected between said plurality of fuel tanks and said fuel pump, said fuel pump being operative to pump fuel to a fuel consuming device, :2. motor for operating said selector valve at high speed when changing from one selector valve position to the next, a fuel pressure and selector valve position responsive switch for controlling said motor, a second switch in the circuit of said motor, means responsive to said second switch when said selector valve approaches port registering position to slow down the rotation of said motor and thereby said selector valve, a switch for each fuel tank, a commutator connected with said selector valve and electrically connected in the cirswitches, and a, relay controlled and tank switches operable cause said selector valve to pass at port registering high speed a position corresponding to an empty fuel tank.

said selector valve to pass at high speed a port registering position corresponding to an empty fuel tank, DAVID SAMIRAN. 

